How To Properly Disassemble And Repair A Bosch Rotary Hammer With Your Own Hands

2023 Author: Philip Bishop | [email protected]. Last modified: 2023-08-25 07:54

• Disassembly procedure Bosch rotary hammer 2-26
• Dismantling the quick release chuck
• How to remove the mode switch
• Dismantling the hammer assembly
• Unusual malfunction of the Bosch rotary hammer
• Bosch hammer drill drills but does not hammer
• Dismantling the electrical part of the Bosch rotary hammer 2-26

The principle of operation of the Bosch 2-26 rotary hammer does not differ from well-known brands of rotary hammers.

The rotating rotor transmits the torque to the intermediate shaft of the mechanical unit of the rock drill, while simultaneously transmitting the translational motion through the rolling bearing to the hammer mechanism of the rock drill and the impact impulse. A rotational moment with a translational shock pulse is transmitted to the working tool. This principle is implemented in all rotary hammers.

But different firms that produce rock drills have their own design features.

Bosch rotary hammers are considered the best in the power tool segment. But nothing is eternal.

If your Bosch 2-20, 2-24, 2-26 rotary hammer has stopped working, then you can restore it yourself. You need to have basic locksmith skills and a little understanding of electrical engineering.

And another important detail, the design of Bosch rotary hammers is so simple that it does not cause difficulties during repair.

When repairing power tools, including repairing Bosch rotary hammers, strictly follow the safety precautions when working with electrical appliances.

To facilitate the repair of the Bosch rotary hammer, its disassembly and assembly, study the tool assembly diagram:

Any disassembly of the bosch 2-26 perforator begins after inspection, test switching and identifying the causes of the device malfunction.

Video disassembly of the Bosch rotary hammer 2-26

Disassembly procedure Bosch rotary hammer 2-26

Since the order of disassembly of drills Bosch 2-20; 2-24; 2-26 is almost the same, consider the sequence of disassembly using the example of a Bosch 2-26 hammer drill.

Dismantling the Bosch GBH 2-26 dre rotary hammer begins with the disassembly of the quick-release chuck.

Dismantling the quick release chuck

Two types of chuck are most commonly used in Bosch rock drills: SDS-plus chucks and SDS-max chucks. The difference between them is in the principle of clamping the tail of the working organ.

The device of the Bosch perforator chuck differs in the design of the tool landing rods, depending on the SDS-plus or SDS-max model. In addition to the listed types of cartridges, there are SDS-top, SDS-quick cartridges.

The procedure for disassembling the cartridge of the Bosch 2-26 perforator is simple:

• remove the rubber tip, pos. 34;
• take out the retaining ring, pos. 87;
• remove the steel washer pos. 833;
• remove the conical spring, pos. 833;
• carefully, so as not to lose it, using a magnet, remove the barrel balls pos. 89.

Inspect all parts of the cartridge carefully.

SDS-plus chucks have been specially developed for drilling tools. The diameter of the tool shanks is 10 mm, the length of the working tool is in the range of 110 … 1000 mm. The drill diameter ranges from 4 to 26 mm.

How to remove the mode switch

Putting the puncher on its side, remove the mode switch pos. 832.

First, turn the switch to the “Drilling” position, press the screwdriver all the way into the end face of the switch button (it is red) and turn the switch counterclockwise by an angle of 70º.

While wiggling the switch handle, pull the switch handle out of the housing.

Dismantling the hammer assembly

Putting the Bosch 2-26 hammer drill vertically on the handle, unscrew the four screws, pos. 90, holding the housing cover of the mechanical assembly.

Press down on the end of the percussion shaft and remove the cover. Black plastic cover.

Now you need to remove the barrel poz.821 and the intermediate shaft pos.826. They are not fixed by anything.

Then, using a screwdriver, you need to remove the bracket pos. 48 of the rolling bearing pos. 830. By the way, in a simple way it is called "drunken bearing". Sequentially removed: sleeve poz.26 and "drunken bearing".

Disassembly of the percussion barrel assembly

• disassembly of the Bosch perforator barrel assembly begins from the side of the cavity, taking out the cylinder pos.26 from it with the drummer pos.27;
• the firing pin assembly must be removed from the cavity;
• from the side of the chuck shaft, remove the retaining ring, pos. 85, the steel ring, pos. 38, and one more retaining ring, pos. 85;
• remove the spur gear pos. 22.

Disassembling the cylinder

A striker, pos. 27, is inserted inside the cylinder, from which it is necessary to remove the rubber ring, pos. 73. For any disassembly, rubber parts must be replaced without fail.

At the opposite end of the cylinder, a hinge, pos. 29, and two flat washers, pos. 41, are inserted.

Dismantling the intermediate shaft

The intermediate shaft is disassembled by removing the shaft, pos. 24, and pulling out the "drunk bearing" from the housing, pos. 77.

The bearings are removed with pullers or manually using a tool.

Unusual malfunction of the Bosch rotary hammer

Bosch rock drills are very reliable. But there are malfunctions that practically do not occur in practice. Below is one of them.

Bosch hammer drill drills but does not hammer

If the hammer drill has stopped hammering, but still allows drilling, the most likely cause may be the destruction of the "drunken bearing". This malfunction is not common and it is not easy to find it.

To fix it, you do not need to go to the repair shop. Any person more or less versed in mechanics will eliminate such a malfunction.

First you need to disassemble the Bosch hammer drill to the intermediate shaft. Disassembly procedure is shown above.

After removing the intermediate shaft, you will get to the "drunk bearing". Broken cage, scattered balls, cage pieces indicate the destruction of the rolling bearing.

Take out the bearing, remove the dirt, all parts of the destroyed mechanism.

You buy a new "drunk bearing", and after lubricating all the parts with new grease, replace and reassemble in the reverse order of the steps for disassembly.

Dismantling the electrical part of the Bosch rotary hammer 2-26

Dismantling the Bosch 2-26 rotary hammer, its electrical part, begins by removing the back cover on the handle of the puncher by unscrewing three screws.

The next step is to remove the reverse switch.

Turn it to neutral and lift it towards you. Reverse switch removed.

To remove the stator cover, you need to hold the mechanical unit in your right hand, and in the left stator housing, pull them in different directions, shaking.

The stator cover will separate.

To separate the rotor from the mechanical unit, it is enough to drag these parts in different directions. The rotor is attached to the mechanical assembly by a small helical gear that is inserted into contact with the large helical gear of the mechanical assembly.

The rotor is freed and you can carefully inspect the condition of the collector, bearings.

To remove the stator, it is enough to remove the protective plastic protective casing, and knock with a wooden blank or mallet on the end of the housing, into which the stator is inserted. Before doing this, do not forget to unscrew the two screws holding the stator in the housing.

The stator is removed, the rotor is taken out, you can proceed to their inspection and fault detection of all parts that make up the electrical part of the Bosch rotary hammer.

When inspecting the disassembled Bosch 2-26 hammer drill, pay special attention to the condition of the carbon brushes, the coating on the brush holders and the reliability of their fastening, the integrity of the reverse switch contacts, the condition of the wire at the point of entry into the hammer drill.

The length of the brushes should not be shorter than 8 mm. There should be no traces of sparking and carbon dust from the brushes on the brush holders, there should be no burnouts or damage to the contacts on the contacts of the reverse switch of the Bosch 2-26 punch.

This concludes the disassembly.

I wish you success!